Contour spray machine



y 1962 F. A. BOWMAN 3,034,475

CONTOUR SPRAY MACHINE Filed Aug. 25, 1958 4 Sheets-Sheet l 66 65 51 3451 73 33 27 f l l 67- 29 58 23 26 \4 L/ Z ////#L////U INVENTOR. 9"FRANCLS' A. BOW

ATTORNEYS y 1962 F. A. BOWMAN CONTOUR SPRAY MACHINE 4 Sheets-Sheet 2Filed Aug. 25, 1958 2 w 7 W2/ 2 m M \m\ a .4 w A 5 2 j 4% @\\A A g 3 a rwx U 0 A mm m z H U 0 m 5w 9 m H 6 m: U 7 3M 3. o h 6 W 2 c: 7 K. 5 w 898 3 42 F 4. INVENTOR.

FRANCIS A.BOWZ\1AN BY P W PM ATTQRZVEYS May 15, 1962 F. A. BOWMAN3,034,475

' CONTOUR SPRAY MACHINE Filed Aug. 25, 1958 4 SheetsSheet 3 JNVENTOR.FRANLIS A. BOW

P 3 m 1- PM ATTORNEYS y 5, 1962 F. A. BOWMAN 3,034,475

CONTOUR SPRAY MACHINE Filed Aug. 25, 1958 4 Sheets-Sheet 4 p .217 398216 I- -l 2.61 3 fl iz 21p? 247 2.

INVENTOR. FRANCIS A. BOI/VZWAN Fem/L011 PM ATTORNEYS United StatesPatent 3,034,475 CONTOUR SPRAY MACHINE Francis A. Bowman, R0. Box 135,Nashua, NH. Filed Aug. 25, 1958, Ser. No. 756,918 8 Claims. (Cl. 118-2)'This invention relates to controlled, or contour spraying of flatsheets of non-symmetrical outline.

The invention is particularly applicable in the coating of large flathides in the tanning industry. It has been customary in this, and manyother arts, to advance articles to be treated. individually andsuccessively along a path and to treat such articles, for example byspray coating, at a treatment station along the path. In the tanningindustry the flat, ungainly hides are usually advanced fiatwise on ahorizontal endless conveyor under reciprocating or rotating spray heads.Sometimes, however, the hides are pasted to large plates which areadvanced in pendant position through a spray station as is US. Patent1,966,093 to Griffin of July 10, 1934.

There has been considerable wastage of the spray liquid when coatingnon-symmetrical articles such as hides, because the sprays have beencontinuous even though the tail, leg or head portion of a hide is ofless width than the body portion. Spray liquid has fallen on the pendantplates or on the horizontal conveyor on each side of the narrow portionsof the hide to no effect and to cause considerable gumming up of theentire mechanism.

It has heretofore been proposed to mount a light sensitive device and alight source on opposite sides of pen dant plates or above and below ahorizontal conveyor to control the valves of the spray guns. However,one or the other such unit is usually in the path of the spray andbecomes gradually clouded by the spray mist. It has also been proposedas in U.S. Patent 2,754,795 to Enssle of July 17, 1956 to actuate thespray guns by a pattern of detectors which sense the irregular outlineof the hide and actuate the spray guns accordingly. As far as I amaware, no one has heretofore successfully controlled spray guns,rotating at high speed, in accordance with the irregular outline of flatsheets or hides passing thereby on a conveyor.

The principal object of this invention is to provide a simple, low cost,control apparatus responsive to the irregular outline, or contour, offlat articles advancing on a conveyor to activate and deactivate amoving spray gun so that only the article is coated and not the entireconveyor.

Another object of the invention is to provide photo electric controlapparatus for a moving spray head which travels with, but leads, a sprayhead to sense predetermined minimum areas of the work to be sprayed andthose areas not to be sprayed.

A further object of the invention is to provide photo electric controlapparatus for a plurality of rotating spray guns wherein the entireapparatus is on the same side of the work as the spray guns androtatable therewith for scanning work areas and intermittently actuatingeach spray gun when travelling over such areas.

Still another object of the invention is to provide photo electriccontrol apparatus wherein the light source is a light, with a divergentnon-focussed, beam, adapted to illuminate a predetermined minimum areaof the work and the light sensitive device is a cadmium sulphidetransistor adapted to respond to reflected light only from such apredetermined minimum area for activating a spray gun or other treatmentdevice.

A still further object of the invention is to provide an improvedspraying machine and method wherein the work is advanced on an openmesh, non reflective conveyor, wherein a flood light and a lightsensitive device continuously scan the non reflective conveyor in aprescribed path and wherein the spray guns are actuated only when apredetermined area of the work on the conveyor intercepts the fiood oflight and reflects the same back to the light sensitive device in apredetermined intensity.

Other objects and advantages of the invention will be apparent from theclaims, the description of the drawings and from the drawings in which:

FIG. 1 is a plan View, partly broken away of a rotating spray machinewith the contour spray control of this invention installed thereon.

H6. 2 is a side elevation on line 2-2 of FIG. 1.

FIG. 3 is an enlarged view of the light sensitive control device of theinvention also illustrating the electrical circuit thereof.

FIG. 4 is an end view on line 44 of FIG. 1.

FIG. 5 is a diagrammatic, perspective view showing the operation of themachine and method of the invention, and

FIG. 6 is an electrical diagram of the preferred circuit for energizingthe circuit shown in FIG. 3.

As shown in the drawings, 2% is a rotary spray machine having side framepieces 21 and 22, an endless conveyor 23 and rotary spray means 24 injuxtaposition to the path of the conveyor and arranged to spray coatarticles such as 25 carried thereby on the conveyor.

*In this invention the endless conveyor 23 is of open mesh material inorder that a light beam directed thereon will pass through without beingreflected thereby. A preferred form of non-reflective conveyor comprisesthe plurality of spaced apart, parallel nylon strands such as 26supported on rolls such as 27 and 28. The shaft 29 of each roll 2'7 or28 is journalled as at 31 and 32 in side frame pieces 21 and 22 and atleast one conveyor roll is driven in the direction of the arrows by agear or sprocket 33 powered by any convenient means such as a motor, notshown. The articles 25 illustrated are non-symmetrical, flat, ungainlyanimal hides which are fed manualtly or automatically in flatwiseposit-ion onto the upper stretch 34 of conveyor 23 and are advanced in ahorizontal directed path while supported at laterally spaced intervalsby the nylon strands 26.

The rotary spray means 24 is centered above the upper stretch 34 ofconveyor 23 and rotatably supported at 35 from one side of the machineby the lateral arm 36, lateral brace 37 and the vertical post 38. Asuitable electric motor 41 and gear reducer 42 are mounted above the arm36 at 35 for rotating the four downwardly and out- Wardly inclined spraygun arms 43, 44, 45 and 46 at a predetermined speed such as 30 rpm.which speed may, however, be varied by suitable rheostat means 47 welllcnown in the art and actuated by a switch 48 from a source of electriccurrent 49. Each spray gun arm such as 43, includes a spray gun such as51 at the lower terminal end 52 of the arm.

Each spray gun 51 is supplied with coating liquid by a supply pipe 54,with atomizing fluid pressure, such as air, by supply pipe 55 and isactuated and deactuated by a normally closed valve 55 and supply pipe(not shown) all through suitable glands well known in the art, forexample, in the De Vilbiss type spray gun. Heretofore, valve 56 has beenopened by fluid pressure such as air from an air supply pipe inaccordance with suitable cam means not shown or control thereof has beenentirely manual.

veyor, passing through into the drip pan 53 after coating 7 the nylonstrands 26 of the conveyor.

The method and apparatus of this invention for avoiding such wastage ofcoating liquid, gumming up of the conveyor and the excessive mist causedby non-contour spraying includes a light beam and a light sensitivedevice both on the same' side of the conveyor and arranged to controlthe spray gun valves in accordance with the scanning of a predeterminedminimum area of the articles to be coated.

As shown, a source of light in the form of an outdoor type lamp 60,preferably of about 150 watts, is mounted in a suitable housing 61, thelatter being conveniently supported by an arm 62, adjustably connectedat 63 to a bracket 64 also carrying the housing 65 of the lightsensitive device. An elongated hood or shield 66 encircles the beam 67from lamp 60 to prevent clouding of the lamp by spray mist and to betterguide the beam 67.

The light sensitive device housing 65 includes a light sensitive devicewhich is preferably in the form of a cadmium sulphide transistor 79* atthe base of an elongated tube 71, the housing 65 being supported on anarm 69 and adjustable by the connection 72, to various angles relativeto the bracket 64 and housing 61.. Tube 71 forms an elognated hood toshield the transistor 78 from the spray mist and to encircle the beam 73reflected thereinto from the work, or articles, 25. The light beam 67 isnot focussed as a spot light to a focal point and the beam does notconverge. Instead, light beam 67 is in the shape of a diverging conewhereby it brightly illuminates, or floods, a circle or oval, zone ofpredetermined area, such as a circle of about six inches in diameter, onthe upper face of the work and illuminates a circle of greater diameteron the drippan 58 when the beam passes through the meshes of theconveyor unintercepted by articles 25. The hoods 66 and 71 convergetoward each other in order that light sensitive device 78 will beactuated by the beam 73 reflected from the articles 25, but device 7%responds only to the intensity of light reflected from the abovementioned minimum predetermined area and does not respond to lesseramounts or to the refiection of a spot light or similar bright focalpoint. A portion of an article one or two inches in width therefore doesnot reflect sufficient light to'transistor 71' to actuate the same, buta portion six or seven inches wide, or more, causes the transistor 70 toactivate the spray guns 51. it will be obvious that the predeterminedminimum area specified above is suitable for animal hides but could beincreased or decreased to other zone dimensions if desired.

As best shown in FIG. 5, a tapered head or tail porticn 74 of a hide 25does not reflect enough light to the transistor 70 until an area such asshown in dotted lines at 75, entirely within the outline of the hide 25,is illuminated by lamp 6%). The spray which is cone shaped, and depositsa cncle of spray such as at '76, then coats the portion 74 rather thanstarting to spray the instant the leading edge 77 of article 25intercepts the light beam 67.

A housing 65 and a housing 61 are mounted angularly in advance of eachspray gun 51in order to scan the open mesh non-reflective conveyor 23 todetermine the presence or absence of the predetermined minimum area ofthe work. A lead of about one foot has been found advantageous to enablethe spray pattern such as 76 to strike the area such as 75 being scannedby the light sensitive device "it? and illuminated by the beam 67.

It should be noted that the. length of the tube or hood 71 iscritical-to the successful operation of theinvention. If it is too long,insuflicient intensity of light reaches the light sensitive device andit too short, the light sensitive device reacts too often. A tube or"about six inches in length and two inches in diameter-has been found togive satisfactory results in the particular relationship of partsdepicted herein. A telescopic hood 1%} and set screw 102 is provided forachieving the exact reaction to reflected light desired. I may use atruncated conical shield, in place of the cylindrical hood 66 in orderto better maintain the dead air space therewithin which keeps the spraymist away from the lamp 60 during rotation of the spray guns 51.

The electrical diagram of FIG. 6 shows the power circuit of the deviceleading from the control box 245, through commutator means to the fourfemale connectors 270, 271, 272 and 273, into which the male connectors,such as 274 (FIG. 3) of each control unit circuit are inserted.

As shown in FIG. 3 each lamp Gil is illuminated by a circuit includingthe lamp, conductor 218, a switch 289, conductors 217, a male connectorsuch as 274 fitting in one of the female connectors 270, 271, 272 or 273(FIG. 6) and a conductor 278. The light intensity of the lamps 69 iscontrolled by means of an auto transformer 239, the transformer 23!)being located in the control box 245 convenient for actuation by theoperator.

The control box 245 includes a centre-off toggle switch 234 D.P.D.T.which placed in one position completes the control unit circuit. In theother position it by-passes the control unit and opens the solenoidvalves 56 for testing the spray guns, washing them of foreign materialor clearing the guns of diiferent colored mixtures and finish.

The control unit circuit includes the cadmium sulphide cells 71? of eachspray gun arm and the cells sense the proper amount of light duringtheir rotation with the spray gun arms. Each cell 70 successively sensesthe intensity of light reflected thereto and, when suflicient, closesthe circuit in the two pole relay coil 201 of its control circuit. Theenergized coil 201 then attracts armature 262 away from contact 203 andagainst contact 204. This in turn completes a circuit including armature202, conductor 215, male connector 274, ground conductor 217, relay coil2G5, conductor 282 and contact 264 to thereby energize the coil of fourpole double throw relay Energization of the relay 205 draws thearmatures 206and 2&7 away from contacts 208 and 210 and into engagementwith contacts 209 and 211. When armature 206 disengages with contact 210and engages contact 21 1 it closes a circuit including male connector274, conductor 215, armature 206, contact 211, pilot light 290,conductor 291, the coil 89 of valve 56 and ground conductor 217. Theenergization of coil 89 causes the spray gun valve 56 to be actuated andcauses spray to be emitted by the spray gun 51 controlled by the abovespecified control circuit. Simultaneously, the change of position ofarmature 207 from contact 208 to contact 209 opens a holding circuit 283and interposes a potentiometer 213 in series with coil 291 and conductor215. This enables the holding flux in armature 202 to be varied bypotentiometer 213 which makes it very easy for armature 202 to return toengagement with contact 2% whenever the light intensity decreases a verysmall amount, i

Any lag or delay in deactuation by the cell 70 is thus overcome and thespray from gun 51 ceases as soon as light intensity in the reflectedbeam 73 becomes even slightly reduced. It will be'understood that mostof the above control and holding circuit is contained in the housings 65on each spray gun arm 43.

As shown in the electric diagram of FIG. 6 the power source is a voltA.C. line leading to control box 245 to which the ground conductor 217is grounded. The ground conductor 217 goes to terminal 229 of autotransformer 230, then to terminal 231 of AC. voltimeter 232, then to theannular bronze disc 297 of the commutator 253.

Conductor 215 goes to fuse 228, thence to the centre terminal 235 offour pole double throw switch 234.

rem terminal 236 of switch 234, conductor 215 goes to terminal 237 ofauto transformer 230. Conductor 215 also leads to the annular bronzering 295 of commutator 253. Conductor 216 goes from terminal 243 ofswitch 234 to the annular bronze disc 298 of commutator 253. Terminals239 and 240 of switch 234 are connected together by conductor 241.Conductor 213 goes from terminal 242 to transformer 230 to terminal 238of A.C. voltimeter 232 and thence to the annular bronze disc 296 ofcommutator 253.

A male connector 247 and a female connector 248 of the four prong type,as shown in dotted lines, may be provided for disconnection purposes.The conductors 215, 216, 217 and 218 are preferably enclosed within thetubular arm, or boom, 96 of commutator means 85, the laterally extendingarm 96 being supported on the post 38 by a suitable bracket 97 andcarrying centralized, stationary discs such as 295 at the other endthereof. A casing, or commutator housing, 99 rotates with the spray gunarms 43 for transferring current thereto, the casing 99 including fourresilient brushes 254, 255, 256 and 257.

The switch toggle of switch 234 and the control knob of transformer 230protrude through control box 245 for easy access by the operator and thecomponents designaated by numerals 228 to 244 are contained within thebox 245.

A junction box 260 is provided on the rotatable spray gun arms andincludes four female four prong connectors 27!), 271, 272 and 273 intowhich the four male connectors such as 274 of the control units may beinserted.

Conductor 216 goes from brush 257 to one side of the coil of a four polerelay 261, then to armatures 262, 263, 264 and 265 and the other side ofthe coil is connected to ground conductor 217. When manual circuit isclosed by the operator at switch 234, the relay 261 attracts armatures262, 263, 264 and 265 against contacts 266, 267, 268 and 269. Thecontacts 266, 267, 268 and 269 are each connected by the four subconductors 216 to one of the terminals of each female connector 279,271, 272 and 273. The remaining terminals of the connectors 270, 271,272 and 273 are connected by the conductors 215, 217 and 218 to theirrespective annular commutator rings 295, 296 and 297.

in operation, the operator places the switch 234 in the manual positionto wash or test the spray guns 51. After this is accomplished, theswitch 234 is placed in the automatic position and light intensity oflamps 60' is adjusted by transformer 230 to the desired voltimeterreading for the particular color to be sprayed. If desired, the controlknob of transformer 230 can be turned to the high stop pin for anincoming voltage check. The AC. voltimeter 232 is for a rapid voltagecheck and serves as a reference indicator for difierent colors only.

I claim:

1. A machine for coating material of irregular shape, said machinecomprising an open mesh, non reflective coveyor for supporting andadvancing said material along a path; rotating support means mounted ata spaced distance from said path, said support means including at leastone spray gun describing a circular path and adapted to coat thematerial on said conveyor; a normally closed spray valve on each saidspray gun and valve control means mounted on said rotating support meansaugularly in advance of each said spray gun, each said valve controlmeans including a light source directing a divergent beam through saidopen mesh conveyor, and adapted to illuminate a predetermined, minimum,critical area of the material on said conveyor, a light sensitive deviceenergized by light reflection from the material on said conveyor whichintercepts said divergent light beam, a tubular hood of predeterminedlength on said light sensitive device for controlling the intensity ofsaid reflected light and electric means, actuated by energization ofsaid light sensitive device, for opening the valve of each said spraygun in accordance with a predetermined intensity of reflected light.

2. A combination as specified in claim 1 wherein said electric meanscomprises a main circuit including a source of electric energy, a springclosed solenoid adapted to open said spray gun valve when energized anda photo relay actuated by said light sensitive device, and holdingcircuit means, including a potentiometer for maintaining the actuationof said spray gun under the control or" said potentiometer.

3. A combination as specified in claim 1 wherein said light sourceincludes a tubular shield in advance thereof which encircles asubstantial dead air space for shielding said light source from spraymist during rotation of said spray guns.

4. A combination as specified in claim 1 wherein said tubular hood istelescopable and includes means for adjusting the overall length thereoffor controlling the intensity of reflected light reaching the saiddevice.

5. Apparatus for spraying fiat sheets of honeymmetrical outlinesupported on a continuously moving, open mesh non-reflective conveyor,said apparatus comprising a plurality of rotating spray guns mountedabove the path of said conveyor for spraying downwardly on eachindividual and successive sheet carried thereunder; an electricallyactuated spray valve on each said spray gun for activating anddeactivating the spray therefrom, and photo electric valve control meansmounted to rotate with, but at a spaced angular distance in advance ofeach said spray gun, each said valve control means including a lightsensitive devicewit-h a tubular hood of predetermined length and a lightsource with a divergent beam, both on the same side of said conveyor,said light sensitive device being responsive to a predeterminedintensity of light reflected from a predetermined area within theoutline of each said sheet to energize and de-energize the valve of saidspray gun.

6. A machine for coating flat Work of irregular outline, said machinecomprising a non reflective open mesh conveyor for supporting andadvancing said flat work along a horizontal path, a plurality ofangularly spaced spray guns continuously rotating above said horizontalpath, each adapted to spray successive annular zones of said conveyor, aplurality of photo electric spray control means, each operably connectedto, one of said spray guns and rotatable therewith and tubular hoodmeans, of predetermined length, mounted on said photo electric spraycontrol means for controlling the activation of each spray gunindividually and successively in accordance with the intensity of lightreflected from predetermined minimum areas within the outline of Workoccupying the annular Zone of said conveyor to be sprayed by said gun.

7. A machine as specified in claim 6 wherein said photo electric spraycontrol means includes a cadmium sulphide cell for sensing the intensityof light reflected from said work, a main spray gun circuit forelectrically actuating each gun in response to a predetermined lightintensity sensed by said cell and a holding circuit, including apotentiometer, for maintaining the actuation of said spray gun under thecontrol of said potentiometer.

8. A machine for coating material of irregular shape, said machinecomprising light pervious conveyor means; a plurality of spray gunsrotating above said conveyor means for coating material carried thereon;light source means mounted in advance of each said spray gun forilluminating a relatively broad area of said material to a predeterminedminimum intensity; light sensitive means mounted in advance of each saidspray gun, including an elongated tubular hood of predetermined lengthdirected toward said illuminated area of said material, for sensinglight reflected only at said predetermined minimum intensity from saidmaterial and electric, spray gun control means including said lightsensitive device for actuating each spray gun individually andsuccessively when a predetermined minimum area Within the outline ofsaid material is scanned by said light source.

UNITED STATES PATENTS Geifs Mar. 9, 1937 Pattison Apr. 28, 1942 Andrewset al -2. Nov. 22', 1949 Giraudo Aug. 28, 1951 Enssle Juiy 17, 1956

